Unpolarized Drell-Yan at Fermilab: (~70 collaborators) → SeaQuest [E-906]: (USA, Japan, Taiwan) → science run: Feb 2014 — spring/summer 2016 Polarized Drell-Yan at Fermilab: (USA, Japan, Taiwan, Spain) (~80 collaborators) → polarized Target [E-1039]: 2016 (for 2 yrs) Stage 1 approval: July-2013 → polarized Beam [E-1027]: >2018 (for 2 yrs) Stage 1 approval: Nov-2012 Present status & needs Polarized Dell-Yan at Fermilab 1 APS LRP: Joint Town Meetings on QCD (13-September, 2014) Wolfgang Lorenzon

2 Planned Polarized Drell-Yan Experiments ExperimentParticles Energy (GeV) x b or x t Luminosity ( cm -2 s -1 ) P b or P t (f)rFOM # Timeline COMPASS ( CERN )  ± + p ↑ 160 GeV  s = 17 x t = 0.1 – 0.32 x P t = 90% f = x , 2018 PANDA ( GSI ) p + p ↑ 15 GeV  s = 5.5 x t = 0.2 – 0.42 x P t = 90% f = x >2018 PAX ( GSI ) p ↑ + p collider  s = 14 x b = 0.1 – 0.92 x P b = 90%2.3 x >2020? NICA ( JINR ) p ↑ + p collider  s = 26 x b = 0.1 – 0.81 x P b = 70%6.8 x >2018 PHENIX/STAR ( RHIC ) p ↑ + p ↑ collider  s = 510 x b = 0.05 – 0.12 x P b = 60%1.0 x >2018 fsPHENIX ( RHIC ) p ↑ + p ↑  s = 200  s = 510 x b = 0.1 – 0.5 x b = 0.05 – x x P b = 60% P b = 50% 4.0 x x >2021 SeaQuest ( FNAL: E-906 ) p + p 120 GeV  s = 15 x b = 0.35 – 0.9 x t = 0.1 – x Pol tgt DY ‡ ( FNAL: E-1039 ) p + p ↑ 120 GeV  s = 15 x t = 0.1 – x – 0.2* P t = 88% f = Pol beam DY § ( FNAL: E-1027 ) p ↑ + p 120 GeV  s = 15 x b = 0.35 – 0.92 x P b = 60%1>2018 ‡ 8 cm NH 3 target / § L= 1 x cm -2 s -1 (LH 2 tgt limited) / L= 2 x cm -2 s -1 (10% of MI beam limited) *not constrained by SIDIS data / # rFOM = relative lumi * P 2 * f 2 wrt E-1027 (f=1 for pol p beams, f=0.22 for   beam on NH 3 ) W. Lorenzon (U-Michigan) 9/10/2014

3 Polarized Drell-Yan: → QCD (and factorization) require sign change → major milestone in hadronic physics (HP13) Extraordinary opportunity at Fermilab (best place for polarized DY) : → high luminosity, large x-coverage → (SeaQuest) spectrometer already setup and running → run alongside neutrino program (w/ 10% of beam) → experimental sensitivity: › 2 yrs at 50% eff, P b = 60%, I av = 15 nA › luminosity: L av = 2 x /cm 2 /s Path to polarized proton beam at Main Injector → perform detailed design studies Cost estimate to polarize Main Injector $10M (total) → includes M&S, labor, 15% project management & 50% contingency Workshop at Hawaii 2014 Joint Mtg (7-Oct-2014) → Polarized Drell ‐ Yan Physics at Fermilab Polarized Beam Drell-Yan at Fermilab (E-1027)

A Novel, Compact Siberian Snake for the Main Injector Single snake design (6.4m long): - 1 helical dipole + 2 conv. dipoles - helix: 4T / 5.6 m / 4” ID - dipoles: 4T / 0.2 m / 4” ID - use one 4-twist helical magnet - 8  rotation of B field - never done before in a high energy ring - RHIC uses snake pairs - 4 single-twist magnets (2  rotation ea) Path to polarized proton beam at MI - detailed design studies: $300k (short-term) - implement modifications to MI $10M (longer-term) Needs - recommendation in LRP document 4 initial design studies

‒ existing SIDIS data poorly constrain sea-quark Sivers function ‒ significant Sivers asymmetry expected from meson-cloud model ‒ first Sea Quark Sivers Measurement ‒ determine sign and value of u Sivers distribution Probe Sea-quark Sivers Asymmetry with a polarized proton target at SeaQuest Polarized Beam Drell-Yan at Fermilab (E-1039) If A N ≠0, major discovery: “Smoking Gun” evidence for L u ≠0 - Statistics shown for one calendar year of running: - L = 7.2 *10 42 /cm 2 ↔ POT = 2.8* Running will be two calendar years of beam time 5

Status and Plans (E-1039) Proton Beam 120 GeV/c Polarized Target SM0 2Tm Ref: Andi Klein (LANL) 500 cm 6 - use current SeaQuest setup, a polarized proton target, unpolarized beam - add third magnet SM0 ~5m upstream improves dump-target separation moves from 0.21 to reduces overall acceptance adds shielding challenges xtxt FMAG KMAG Target Polarization: 85% Packing fraction 0.6 Dilution factor: Density: 0.89 g/cm 3

7 Beam Pol. Target Pol. Favored Quarks Physics Goals (Sivers Function) L sea sign change sizeshape COMPASS ✕✔ valence ✔✕✕✕ E-1027 ✔✕ valence ✔✔✔✕ E-1039 ✕✔ sea ✕✔✔✔ E-10XX ✔✔ sea & valence Transversity, Helicity, Other TMDs … COMPASS, E-1027, E-1039 (and Beyond)

A high-luminosity polarized Drell-Yan program at the Fermilab Main Injector with both polarized beams and targets is endorsed by the U.S. QCD community. Proposed Polarized Drell-Yan Recommendation Text for the QCD Town Meeting 8